Message Name:

AC/DC CABIN BUSS NOT POWERED AFTER EMS CDU REPLACEMENT

The AC cabin BUS and/or DC cabin Bus not powered after EMS CDU or SPDA replacement or a Virgin Start.

• AC and DC Cabin BUS Isolation Control are not ON
• AC and DC Cabin Switches Control are not IN
• AC and DC Cabin Feeders are not IN

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter:

• EMS CDU Cabin Feeders Switch Control and/or Circuit breaker Default to OFF

NOTE: If AC cabin BUS and/or DC cabin Bus are found not powered without maintenance action performed, please refer to SFP OBS fault - CABIN SYSTEMS UNPOWERED AT AIRCRAFT POWER UP

If the AC and DC cabin power are not available after an EMS CDU, SPDA replacement or after a virgin start, verify:

1. On EMS CDU, select BUS EMER CONT.  On page 1/2 and 2/2, make sure AC and DC cabin power BUS isolation controls are ON.
2. On EMS CDU, select SYS CNTL key. On page 2/3 and 3/3, make sure all AC and DC cabin power switches control are IN.

None

1. Make sure AC and DC cabin power BUS isolation control are IN on EMS CDU.

   1. If one or more are found "OUT", set them to "IN" and do close out
   2. If they are all "IN" continue with next step

2. Make sure all AC and DC cabin power switches control are IN on EMS CDU.
3. Do close out.